In endoscopic surgical procedures, relatively narrow surgical instruments are inserted into the patient's body so that the distal (i.e., working) ends of the instruments are positioned at a remote interior site, while the proximal (i.e., handle) ends of the instruments remain outside the patient's body. The surgeon then manipulates the proximal handle ends of the instruments as required so as to cause the distal working ends of the instruments to carry out the desired surgical procedure at the remote interior site.
In order to visualize what is taking place at the remote interior site, the surgeon also inserts an endoscope into the body during the endoscopic surgery, together with an appropriate source of illumination.
The endoscope generally comprises an elongated shaft having a distal end and a proximal end, and at least one internal passageway extending between the distal end and the proximal end. Image capturing means are disposed at the distal end of the shaft and extend through the shaft's at least one internal passageway, whereby the image capturing means can capture an image of a selected region located substantially adjacent to the distal end of the shaft and convey that image to the proximal end of the shaft. Viewing means are in turn disposed adjacent to the proximal end of the shaft, whereby the image obtained by the image capturing means can be conveyed to a display device which is viewed by the surgeon.
The image capturing means and the viewing means commonly utilize one of several different arrangements to capture an image at the distal end of the shaft and to present it to the surgeon.
For example, in one arrangement, the image capturing means comprise a bundle of fiber optic filaments which extend through the shaft's at least one internal passageway. A lens is positioned at the distal end of the shaft to focus the desired image onto the distal end of the fiber optic bundle. The fiber optic bundle then conveys the captured image to the proximal end of the shaft, where it is received by the viewing means. In this arrangement, the viewing means may comprise a display device which is in the form of a conventional optical viewer or eyepiece which is viewed directly by the surgeon. Alternatively, and more relevant to the present invention, the viewing means can comprise an appropriate image sensor, e.g. a charge coupled device ("CCD") element or video tube, which can receive the captured image from the proximal end of the fiber optic bundle and generate corresponding video signals which are representative of the captured image. These video signals are then displayed on an appropriate display device (e.g. a monitor) which is viewed by the surgeon.
In a second arrangement, the image capturing means comprise a CCD element which is disposed at the distal end of the shaft, and wires which extend through the shaft's at least one internal passageway. An appropriate lens focuses the desired image onto the CCD element's light-receiving surface, and the wires convey the CCD element's video output signals to the proximal end of the shaft. These video signals are then displayed on an appropriate display device (e.g. a monitor) which is viewed by the surgeon.
In a third arrangement, the image capturing means comprise a so-called rod-lens system. In this embodiment, a series of rod lens elements are arranged within the shaft's at least one internal passageway so as to capture the desired image at the distal end of the shaft and convey that image to the viewing means located at the proximal end of the shaft. With this arrangement, the viewing means can comprise a display device in the form of a conventional optical viewer or eyepiece which is viewed directly by the surgeon. Alternatively, and more relevant to the present invention, the viewing means can comprise an appropriate image sensor, e.g. a charge coupled device ("CCD") element or video tube, which can receive the captured image from the proximal end of the rod-lens system and generate corresponding video signals which are representative of the captured image. These video signals are then displayed on an appropriate display device (e.g. a monitor) which is viewed by the surgeon.
Regardless of the particular construction involved, all prior art endoscopic viewing systems tend to suffer from one significant deficiency. In particular, all prior art endoscopic viewing systems suffer from the fact that, in some situations, the surgeon's normal sense of kinesthesia will be lost while observing the endoscopic surgical procedure through an endoscope.
More particularly, and looking now at FIG. 1, during a typical endoscopic procedure, a surgeon 5 uses an endoscope 10 to view various objects (e.g. the body structures 15A and 15B and the surgical instrument 20) which are located at the remote interior site. To this end, endoscope 10 is typically connected to a monitor 25 by wires 30 such that the monitor's screen 35 will display an image of body structures 15A and 15B and surgical instrument 20 which are located at the remote surgical site.
In the situation shown in FIG. 1, body structure 15A resides to the surgeon's left and body structure 15B resides to the surgeon's right. Furthermore, as the surgeon moves surgical instrument 20 left to right through the surgical site, the surgical instrument will move away from body structure 15A and toward body structure 15B.
In a corresponding fashion, when the surgeon views the surgical site on the monitor's screen 35, the surgeon will see body structure 15A to the left and body structure 15B to the right. In addition, as the surgeon moves surgical instrument 20 from left to right across the surgical site, surgical instrument 20 will appear to move from left to right on the monitor's screen 35. Thus there is a proper correspondence between the surgeon's physical sense and what the surgeon sees on screen 35. This proper correspondence occurs because, in the situation shown in FIG. 1, surgeon 5 and endoscope 10 both face in substantially the same direction. As a result, the surgeon's normal sense of kinesthesia (i.e., the proper correspondence between tactile sense and visual sense) is effectively maintained by the endoscopic viewing system during the surgical procedure.
A somewhat different situation is shown in FIG. 2. Here, the position of surgeon 5 has remained the same relative to the surgical site, but the position of endoscope 10 has changed. As a result, surgeon 5 and endoscope 10 now face in substantially opposite directions. From the surgeon's physical perspective, body structure 15A still resides to the surgeon's left and body structure 15B still resides to the surgeon's right. Furthermore, as the surgeon moves surgical instrument 20 from left to right through the surgical site, the surgical instrument will still be moving away from body structure 15A and toward body structure 15B.
Unfortunately, this is not what appears on the monitor's screen 35. Instead, when the surgeon views the surgical site on the monitor's screen 35, the surgeon will see body structure 15A to the right and body structure 15B to the left. In addition, as the surgeon moves surgical instrument 20 from left to right in real space, the surgical instrument will appear to move from right to left on the monitor's screen 35. Thus there is no longer a proper correspondence between the surgeon's physical sense and what the surgeon sees on screen 35. This is because, in the situation shown in FIG. 2, surgeon 5 and endoscope 10 face in substantially opposite directions. As a result, the surgeon's normal sense of kinesthesia is not maintained by the endoscopic viewing system during the surgical procedure.
It is well recognized that the loss of the surgeon's normal sense of kinesthesia can cause the surgeon to become confused or disoriented during a surgical procedure. As a result, the procedure may take longer for the surgeon to perform. In some cases, this confusion or disorientation may actually result in the procedure being conducted improperly, possibly with some unintended harm occurring to the patient. Thus it has also been well recognized that, ideally, surgeon 5 and endoscope 10 should both always face in substantially the same direction, in the manner shown in FIG. 1. In this way the surgeon's normal sense of kinesthesia will always be maintained by the endoscopic viewing system during the surgical procedure.
Unfortunately, it has also been found that this is not always possible. In many cases, the orientation of the surgeon and the orientation of the endoscope may be dictated by other considerations. For example, when performing surgery on the interior of a joint, the patient's anatomy may dictate the number and location of the various entry portals so as to minimize damage to nerves, blood vessels, ligaments and the like. The number and location of these entry portals may not permit the surgeon and the endoscope to both face in substantially the same direction. Furthermore, in many cases, the orientation of the surgeon and the orientation of the endoscope may need to change several times during the surgical procedure so as to afford the desired approaches. Thus it will be seen that, in many cases, surgeon 5 and endoscope 10 may well end up facing in substantially opposite directions, in the manner shown in FIG. 2. As noted above, when this occurs, the surgeon's normal sense of kinesthesia will not be maintained by the endoscopic viewing system during the surgical procedure, with potentially disastrous results.
Analogous problems exist in many other fields as well. More particularly, numerous situations exist where an operator must perform tasks at a remote site using extended tools, with the operator visualizing the procedure indirectly through a remote viewing system. Examples of such fields might include nuclear material handling, toxic chemical handling, infectious material handling, closed pipeline work and remote robotic work, among many others. In all of these cases, the orientation of the operator may differ significantly from the orientation of the viewing system during some or all of the procedure, so that the operator's normal sense of kinesthesia may not be maintained by the viewing system during the remote procedure. This can result in the operator becoming disoriented or confused during the procedure. As a consequence, the procedure can take longer to complete, and/or the operator may make potentially serious errors during the procedure.